Control mechanism for the needle bar of sewing machines



May 1, 1962 M. ARMBRUSTER 3,031,988

CONTROL MECHANISM FOR THE NEEDLE EAR oF SEWING MACHINES www@ May 1, 1962 M. ARMBRUSTER 3,031,988

CONTROL, MECHANISM FOR THE NEEDLE BAR oF sEwING MACHINES Filed Dec. 2, 1958 6 Sheets-Sheet 2 www@ May '1, 1962 M. ARMBRUSTER I 3,031,988

CONTROL. MECHANISM FOR THE 4NEEDLE BAR OF SEWING MACHINES Filed Dec. 2, 1958 6 Shefcs-Shee'o 5 May l, 1962 M. ARMBRUSTER 3,031,988

CONTROL NEcHANIsM FOR THE NEEDLE EAR oE SEWING MACHINES Filed Dec. 2, 1958 6 Sheets-Sheet 4 /N VF NTO/K7 Max ARME/(70675? May 1, 1 962 M. ARMBRusTI-:R 3,031,988

CONTROL MECHANISM FOR THE NEEDLE BAR OF SEWING MACHINES Filed Dec. 2, 1958 6 Sheets-Sheet 5 May 1 1962 M. ARMBRusTl-:R 3,031,988

CONTROL NEcHANIsM FOR THE NEEDLE BAR oE SEWING MACHINES Filed Dec. 2, 1958 6 Sheets-Sheet 6 United States Patent Oiiice 3,031,988 Patented May l, 1962 3,031,988 CONTRGL MECHANISM FOR THE NEEDLE BAR F SEWING MACHINES Max Armbruster, Karlsruhe-Durlach, Germany, assignor to Gritzner-Kayser Aktiengesellschaft, Karlsruhe-Durlach, Germany Filed Dec. 2, 1958, Ser. No. 777,729 Claims priority, application Germany July. 22, 1958 Claims. (Cl. 112-158) The present invention relates to sewing machines, and more particularly to sewing machines constructed to turn out decorative designs, zig-zag and fancy stitch patterns besides straight seams.

The invention is particularly directed to sewing machines provided with a plurality of cam discs that have contours suitably shaped to generate a variety of stitch patterns in cooperation with one or more iingers or cam followers. The latter are arranged for selective engagement with the former; the arrangement being such that an externally operable member selects the particular operative finger or cam follower combination required for the selected stitch pattern, all other cams and followers remaining inoperative. The motion of the operative follower finger may, for example, be oscillatory, as determined by the contour of the cooperable operative cam. The oscillatory motion is then imparted to the needle bar of the machine in a direction transverse to the normal upand-down reciprocating motion, resulting in a zig-zag stitch pattern.

In earlier machines of the above character a single follower or finger element was employed, positionable selectively to engage a respective cam in sequence of selection. This arrangement was sufficiently satisfactory where the number of available stitch patterns and consequently that of the required cams was small.

The mechanism comprising cams and follower is of necessity located within the longitudinal horizontal arm of the sewing machine, so that space limitations dictated reduction in cam thickness with increase in the number of stitch patterns. This in turn necessitated a follower finger of greatly reduced thickness to avoid simultaneous engagement of several cams. However, such reduced finger thickness presented a new possibility of error in registration, i.e. improper engagement of a non-selected cam; this was due to the requirement of but a short travel distance for the finger from engagement of one cam to the engagement of the next one responsive to change in selection. This led to resort to a selector system with multiple fingers, each coordinated with a respective cam and swingable permanently in the plane of they cam.

In a well known selector arrangement of the multiple finger type, it was customary to support the feelers coaxially by means of a spring loaded rocker or like member. The selector apparatus for establishing the connection between the rocker and the individual stitch pattern generating cam disc consisted of a pulling element or draw key. Such transmission means by virtue of its physical location directly in the axis of rocker and fingers could easily result in registration errors, i.e. improper'actuation of a non-selected finger. This structure ensued also unnecessary cam and follower wear and objectionable rattle noise.

The present invention contemplates an arrangement of the above said general character, which avoids these and many other disadvantages, and which assures high accuracy in the selection of the proper cam disc in accordance with the particular setting of the selector means. Moreover, the apparatus according to the present invention admits of relatively inexpensive manufacturing. These advantages do not depend on the number of discs or particular arrangement of the selector means. yIt is fully effective, even in the case, where the number of discs is relatively large and where a selector control is required which is quite remote from the cams and followers.

It is accordingly a principal object of the present invention to provide means conductive to a highly sensitive and reliable stitch pattern selector mechanism of the general character described, which avoids the disadvantages of previously known stitch pattern selecting mechanisms.

Another and more specific object of the invention is to provide means affording a sturdy and rigid stitch selecting mechanism which ist-free from registration errors and thus assures proper generatori of the respective selected stitch pattern.

A still further object of the invention is to provide means ensuring a very efficient stitch pattern selecting mechanism which includes means for disengaging nonselected cam followers, thereby assuring a long operating life for the cams and followers and minmizing any friction and contact noise in the machine.

Yet another object of the invention is to provide a stitch pattern selector mechanism, which includes cam members that are readily removable, replaceable and interchangeable as a unit, whereby servicing thereof is greatly facilitated.

Yet a further object of the invention is to provide means devising a simplified stitch selecting mechanism that may be manufactured at relatively low cost.

Still a further object of the invention is to provide means redounding to an easily operable stitch selecting mechanism which is capable of changing a selected stitch pattern without the necessity to shut off power to the sewing machine or to interrupt the needle operation, and which is nevertheless foolproof as to the propriety of stitch pattern selection.

Stili another object of the invention is to provide means instrumental to an efiiciently and reliably operable control mechanism for zig-zag sewing machines which besides the usual cam disc pack and feeler or follower ringer arrangement includes a specially designed selector mechanism for operating the feeler fingers relative to the cam discs and for actuating simultaneously therewith large scale stitch pattern indicator means, whose pointer will move commensurate with the varying inoperative and operative positions of the selector mechanism, so that even persons who are technically untrained or generally adverse to machine operation may easily manipulate the sewing machine like a radio or television set.

In a preferred embodiment of the invention each of the feelers is provided with a retracting spring thereby assuring disengagement of all but the selected cam follower. The latter is brought to engagement by means translatable in parallel relation to the axes of the cams and followers responsive to operation of the selector and arranged to engage the rear surface of the selected finger to urge the same into engagement of its coordinated cam against the action of the coordinated retracting spring.

Accurate registration is assured by inclusion in the selector mechanism of a threaded spindle operatively connected to an external operable knob or like element for imparting translational movement to a slide which in turn imparts its motion to the translatable finger engaging means. The fact of disengagement of non-selected cam follower greatly minmizes noise and prolongs the life of the stitch pattern selecting mechanism including the cams and followers.

Further advantages and novel features of the invention will be apparent upon consideration of the following more detailed description when considered together with the accomp anying drawings in which:

FIG. 1 is a fragmentary top plan view of a sewing machine with'stitch pattern control means constructed in accordance with the invention, certain parts of said machine being broken away for the sake of clarity;

FIG. 2 is an exploded and perspective illustration of the machine of FIG. 1;

FIG. 3 is a side elevational view of the machine of FIG. 1 with parts thereof seen in one position;

FIG. 4 is a view similar to that of FIG. 3 with parts of the sewing machine shown in a different position;

FIG. 5 is a fragmentary sectional view of parts of the sewing machine in a position different from that seen in FIG. 1;

FIG. 6 is a fragmentary sectional view of parts of the sewing machine in a position different from that seen in FIG. 5;

FIG. 7 is a partial side elevational View of the sewing machine pursuant to the invention depicting the horizontal arm of the machine with a window exposing various stitch patterns and a control or selector knob therefor.

Referring to the drawings and particularly to FIGS. l and 2, reference numeral 1 designates a bearing block which is secured at its transverse rearward end to the inner wall of the freely extending horizontal hollow arm 3 (FIG. 1) of a sewing machine by means of screws to be inserted in bores 2. Transversely and forwardly extending brackets 4 of the bearing block 1 receive within aligned bores 5 a pin 6 which also extends through a bore 7 of a carrier or support S which is suitably accommodated within arm 3 (not shown). Pin 6 may be secured to said carrier by means of a set screw 9. At its opposite end the carrier frame S is provided with a U- shaped clamping member 10 which is secured to a thereto conforming part (not shown) within arm 3 of the sewing machine at 11. Bearing block 1, carrier 8 and arm 3 of the sewing machine constitute rigid unity and therefore the supports associated therewith are disposed in fixed spaced relation to one another.

A support bearing 12 (FIG. 2) of a downwardly extending supporting bracket 13, as well as a further bearing support 14 (FIG. l), all unitary parts of the carrier 3 and located near member 10 receive a shaft or axle 15 on which a tubular shaft 18 is rotatably mounted. On the axial ends of shaft 18 there are seated a worm gear 16 and a pinion 17 disposed intermediate arms 13 and 14 within carrier 8.

Worm gear 16 is driven in a well know manner by means of a worm drive shaft (not shown) which is in turn driven ultimately by the main shaft (not shown) located in the sewing machine. The pinion 17 engages a spur gear 19, which is mounted with its hub 20 for rotation in unison with a shaft 23, that extends transversely of carrier 8 approximately centrally thereof. Bearing support 21 for shaft 23 (FIG. 1) is fixed to the carrier 8. Gear 19 with its hub 20 is axially maintained in place by a retaining ring 22. Hub 20 is coupled to shaft 23 by means of a stud or cotter pin 24 which passes through a slot 25 of the hub 20 and which is rotatably mounted at its other end in a bearing support 26 (FIG. 2) of the carrier 8. Pin or shaft 23 is maintained in place in axial direction by means of a safety lever 29 which is pivoted on a collar screw 27 (FIG. 1) and is urged to operative position by means of a spring 28 wound around screw 27. The safety lever 29 engages pin or shaft 23 in an annular groove 30 and is provided with an angularly extending handle piece 31 (FIG. 2) for manual actuation.

The stitch pattern generating cam dises 32 are a1'- ranged in a stacked assembly or pack. They are supported by the shaft 23 and are coaxially coupled to the gear 19 by means of a screw 33 fastened thereto. The discs 32 are thus driven by means of the machine shaft (not shown) via pinion 16, shaft 18, worm gear 17, and gear 19 with greatly reduced speed. Since the shaft 23 is readily removable and interchangeable, it is easy to remove the disc pack and to replace it by another one.

An axle or pin 34 is disposed in the arm 3 of the machine and extends transversely thereof. It supports a swingable member or rocker 35 which includes two end bracket plates 36 and 37 which are rigidly interconnected by means of pins 38, 39 and 40 extending in parallel relation to axle 34. A winged link lever or like connecting means 42 is pivoted to the plate 36 by means of a lug 41, and is at its other end pivoted to stub 43 which has secured thereto an upper end of a double armed rocker lever 44. The latter is swingably supported relative to the carrier 8 by means of the previously mentioned axle 15 at whose remote end it is axially maintained by means of a pin 45.

A sliding block guide member or plate 47 is secured to the lever 44 near the lower end thereof by means of a screw 46. A sliding block 4S is mounted within the plate 47 for performing reciprocating sliding motion. The block 48 pivotally supports a connecting lever 50 at one end of the latter by means of a screw 49. The other end of the lever 5t) is pivotally interconnected with the needle bar frame 51a whose needle bar 51 is driven by the machine shaft (not shown) in a well known manner for up and down motion. The oscillatory motion of rocker or frame 35 is imparted to the needle bar 51 to an extent which is the greater the distance between the screw 49 and the axle 15 amounts to as dictated by the requirements of the stitch selecting apparatus. In the case of displacement of parts 49 and 50 to coincide with each other as shown in FIG. 3, the selected width of the stitch pattern is zero, i.e. a straight line stitch pattern is obtained.

The rocker or oscillatory frame 35 is not directly mounted on the axle 34 for free swinging motion but by means of a sleeve 52 (FIG. 2) which extends between the plates or brackets 36 and 37 forming axle means and on which is mounted for free rotation a set of single independent cam follower feelers or fingers 53.

The axial disposition of the sleeve 52 is maintained by means of a set collar 54 (FIG. l) that is inserted intermediate of the row of fingers and the plate 37. The feelers 53 are mounted for swinging movement, independently of one another relative to the oscillatory frame 35 and coaxially therewith.

One feeler is provided for each one of the cam discs 32. As will be seen hereinafter, stitch pattern selector means cause selective engagement of one of the feelers with its coordinated disc. The generally non-circular peripheral cam contour gives rise to a rocking motion of the associate-d feeler which is ultimately translated via frame 35 and imparted to the needle bar 51 to produce a zig-zag pattern in accordance with the corresponding contour of the selected cam disc.

Each of the stitch pattern cam discs 32 is coordinated with a feeler 53 with the exception of the disc nearest the gear 19, as is most easily seen in FIG. 1. The latter disc may be utilized in any desired manner for actuation of other sewing machine parts (not shown), for example the cloth feed mechanism. At the opposite side of the row of discs 32 there is provided a supporting plate 55 which, insofar as its coordinated finger is concerned, is equivalent to a disc with exactly circular contour.

A roller 56 is mounted for axial sliding movement in parallel relation to axle 34 on a connecting pin 40 which is fixed to the rocker or frame 35. A tension spring 57 (FIG. 3) is hooked to the plate 37 and is effective to rotate the rocker 35 about its axis 34 to such an extent as to cause engagement of the roller 56 With a portion of one of the selected feelers thereby to cause such finger to engage at its front end with and follow the contour of its associated stitch pattern disc.

In this manner, the oscilaltory frame 35 performs swinging movements in accordance with the elevations and depressions forming the peripheral contour of the selected disc and imparts these movements in the described manner via connecting means 42 to the needle bar 51. The inoperative feelers or fingers 53 are maintained in their retracted and disengaged position by means of corresponding individual retaining springs 58, held in position Yby clamp plate structure 60, 61, 62 and 59, whereby unnecessary wear of the discs 32 and rattle noise are avoided and long life is assured for the discs and coordinated feelers.

The retaining springs 58 are secured side-by-side to the carrier 8 by means of two screws 59 and are located with their respective ends between base plate 60 (FIG. 3) and ltop plate 61. The base plate 60 raids in positioning the fingers 53 laterally in exact alignment with respective coordinated discs by means of two lateral extensions 62 (FIG. 2) forming parts of said base plate.

A roller or like element 56 is slidable for select-ive engagement with a selected finger 53. The selector mechanism for controlling element 56 will next be described:

The bearing block i1 is provided with arms 63 which serve as lbearing means for a rotatable spindle 65 whose axis is parallel to pin or shaft 40, and which is provided with a helical or thread forming groove 64. A sleeve 66 is seated on spindle 65 'and is provided with an arm 67 which in turn has a fork-like extension or end member 68, that is adapted to engage roller 56, so as to permit relative motion o-f fork member and roller with rocking of oscillatory frame 35, as is most clearly seen in FIG. 3. A set screw 69 (FIG. 2) is secured to the interior of sleeve 66 and is arranged to move within helical groove 64, so as to transform translatory motion of the arm 67 along rod 70 which is connected to bearing arm 63, whereby upon rotation of the spindle 65, the fork or end member 68 entrains roller 56 and displaces the latter in a direction parallel to the axis on which the fingers 53 may be shifted or displaced (FIGS. 5 and 6).

To this end, it is necessary to provide further operable means hereinafter described, for first removing the roller 56 from the range of swing of the lingers 53. It is this feature which permits selection change without machine interruption.

A ratchet wheel 71 is rigidly secured to the rear end of spindle 65 and cooperates with a pawl 74 which is pivoted on a collar screw 72 (FIG. l) and is loaded by means of a spring 73, thereby to maintain the fork member 68 in the particular selected position to which the roller 56 has been displaced through action of said fork member, whereby the roller or like element 56 engages a particular selected one of the fingers 53. A pinion 75 is rigidly secured to spindle 65 adjacent the opposite end thereof. Pinion 75 meshes with a gear 76 which is rotatably mounted within the machine arm 3 (FIG. l) by means of a hub 77 (FIG. 2). A selector knob or like operable means 78 is operatively secured to the hub 77 for rotation in unison therewith, so that upon operation of knob 78 the displacement of roller 56 occurs along the row of lingers 53 via the aforesaid described transmission means 76, 75, 71, 68, 56 for the selector mechanism.

The selector knob 78 is further provided with a spindle 79 (FIG. 3) that extends from without into the interior of the machine housing arm 3. Said spindle 79 is provided at its remote end with a conically shaped portion indicated as at 80. The selector knob 78 is further axially displaceable relative to the hub 77, and is normally spaced away from machine housing arm 3 by means of a spring (not shown) to such an extent that the reduced conical end 8i) of spindle 79 is approximately in an even plane with a three-armed lever 81 (FIG. 3), which is pivoted as at 82 in the machine arm. One end of lever 81 is situated adjacent a pin 83 which extends forwardly of bracket plate 37 of rocker or oscillatory frame 35 (FIG. 2).

Upon pressing the selector knob 78 in the direction toward the interior of the machine arm support 3 the remote and tapered or conically shaped end 80 of spindle 79 engages the adjacent arm of lever 81, rotating the same counterclockwise as viewed in FIG. 3 about pivot 82. Accordingly, the frame 35 and necessarily roller or like element 56 are ydisplaced in clockwise direction about pin 34, whereas the fingers 53 are retained in position by means of an abutment or stop member 84 (FIG. 4).

In this manner, the roller 56 will be displaced outside of the range of swing of the cam followers or feelers 53 so that said roller 56 admits of forward and rearward axial slidable selector displacement in the above described manner. Upon release of the selector knob 78 this knob is then restored to its normal outward position indicated in FIG. 3 yby means of the above mentioned loading spring (not shown), whereupon, the selector device assumes the state and condition illustrated in FIG. 3 due to .the action of spring 57 (partly indicated).

'Ilhe stitch pattern corresponding to the selected prosition of the roller 56 is displayed in the following manner:

The `spindle 65 is provided with a further pinion 85 which is coupled for rotation in unison therewith and which meshes with a gear 86 which in turn is journaled within the machine arm 3. A sprocket wheel 87 is spaced from and secured to gear 86 for rotation in unison therewith and engages a sprocket belt 88 (FIG. 2) which is supported at its remote end by ya guide roller 89. Belt 88 carries a pointer 90. This pointer is employed to indicate replica or like indicia on a scale or plate corresponding to selected stitch patterns arranged side-by-.side on said plate, which is located in an opening of arm 3 and somewhat remote from, but on the same machine side at which knob or operable means 78 is located (FIG. 7).

FIG. 7 shows pointer 90 in one position on scale 160 corresponding to the position of the abutment or roller 56, for instance in accordance with the position seen in FIG. 1, whereas the position of the pointer 99a corresponds to the position of the abutment or roller 56 seen in FIG. 6.

It can thus be seen that there has been provided in accordance with the present invention a control mechanism for the needle bar of a sewing machine having a hollow arm support, stitch pattern indicating means, stitch pattern control means located within said arm support and having a set of rotatably driven cam discs and a plurality of feeler fingers disposed for selective displacement relative to said cam discs, whereby a predetermined feeler finger may be shifted for contact with a coordinated respective cam disc, thereby to translate motions o-f said predetermined finger caused by said respective cam disc to the needle bar in accordance with a selected stitch pattern, so that said needle bar is actuated via movement translating means extending from said needle bar to an oscillatory frame, with which said predetermined feeler finger is connected.

Said indicating means comprise a carrier plate provided with a plurality of replica of stitch patterns which are arranged in spaced apart and side-by-side relation, a pointer located above said plate for sweeping over said replica of said plate, said plate and said pointer being set in an opening of said arm support for perception from therewithout, first means carrying said pointer rearwardly of said plate and within said arm support, second means located remote from said carrier plate and extending from without said arm support thereinto and operatively connected to said first means thereby to impart sweeping motion to said pointer relative to said carrier plate, and feeler finger selector means located adjacent said feeler fingers within said arm support and operable by said first means commensurate with the sweep of said pointer, so that a corresponding one of said feeler fingers is shifted relative to the remaining fingers for contact with the respective cam disc, thus causing performance of said selected stitch .pattern by said needle bar.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A control mechanism for a sewing machine having a frame, a needle bar mounted on said frame for swinging movement, and a swing member connected to said needle bar for effecting such swinging movement, comprising a rotatable cam shaft, a plurality of cam discs each having a predetermined contour corresponding to an associated stitch pattern mounted on said cam shaft for rotation therewith, a yfollower shaft adjacent said cam discs, a plurality of follower fingers corresponding in number to said cam discs pivotally mounted on said follower shaft, a double arm rocking frame pivotally mounted adjacent said follower fingers having one arm connected to said swing member to control the movement thereof and a control arm extending alongside said cam discs, a cam actuating member shiftable along said control arm into alignment with a predetermined one of said follower fingers, means to bias said rocking lever to urge said cam actuating member into engagement with the cam with which it is in alignment, said follower fingers being oscillated by rotation of said cam to correspondingly oscillate said actuating member, said control arm, said rocking frame and said swing member to control the swinging movement of said needle.

2. A control mechanism for a sewing machine having a frame, a needle bar mounted on said frame for swinging movement, and a swing member connected to said needle bar for effecting such swinging movement, comprising a rotatable cam shaft, a plurality of cam discs having a predetermined contour corresponding to an associated stitch pattern mounted on said cam shaft lfor rotation therewith, a follower shaft adjacent said cam discs, a plurality of follower fingers corresponding in number to said cam discs pivotally mounted on said follower shaft, a double `arm rocking frame pivotally mounted adjacent said follower fingers having one arm connected to said swing member to control the movement thereof and another control arm extending alongside said cam discs, a cam actuating member shiftable along said control arm into alignment with a predetermined one of said follower fingers, means to bias said rocking lever to urge said cam actuating member into engagement with the cam with which it is in alignment, said follower fingers being oscillated by rotation of said cam to correspondingly oscillate said actuating member, said control arm, said rocking frame and said swing member to control the swinging movement of said needle, and selector means connected to said actuating member to shift said actuating member along said control rod into alignment with a predetermined one of said follower fingers.

3. A control mechanism for a sewing machine having a frame, a needle bar mounted on said frame for swinging movement, and a swing member connected to said needle bar for effecting such swinging movement, comprising a rotatable cam shaft, a plurality of cam discs having a predetermined contour corresponding to an associated stitch pattern mounted on said cam shaft for rotation therewith, a follower shaft adjacent said cam discs, a plurality of follower fingers corresponding in number to said cam discs pivotallymounted on said follower shaft, a double arm rocking frame pivotally mounted adjacent said follower fingers having one arm connected to said swing member to control the movement thereof and a control arm extending alongside said cam, a cam actuating member shiftable along said control arm into alignment with a predetermined one of said follower fingers, means to bias said rocking lever to urge said cam actuating member into engagement with the cam with which it is in alignment, said follower fingers being oscillated by rotation of said cam to correspondingly oscillate said actuating member, said control arm, said rocking frame and said swing member to control the swinging movement of said needle, and selector means connected to said actuating member to shift said actuating memberalong said.

control rod into alignment with a predetermined one of said follower fingers, said selector mechanism including a rotary control arm having a spiral groove defined therealong, a member having a portion in said groove and shiftable along said arm upon rotation of said control arm, said member being engageable with said actuating member to shift said actuating member into alignment with a predetermined follower finger.

4. A control mechanism for a sewing machine having a frame, a needle bar mounted on said frame for swinging movement, and a swing member connected to said needle bar for effecting such swinging movement, comprising a rotatable cam shaft, a plurality of cam discs having a predetermined contour corresponding to an associated stitch pattern mounted on said cam shaft for rotation therewith, a follower shaft adjacent said cam discs, a plurality of follower fingers corresponding in number to said cam pivotally mounted on said follower shaft, a double arm rocking frame pivotally mounted adjacent said follower fingers having one arm connected to said swing member to control the movement thereof and another control arm extending alongside said cam, a cam actuating member shiftable along said control arm into alignment with a predetermined one of said follower fingers, means to bias said rocking lever to urge said cam actuating member into engagement with the cam with which it is in alignment, said follower fingers being oscillated by rotation of said cam to correspondingly oscillate said actuating member, said control arm, said rocking frame and said swing member to control the swinging movement of said needle, and selector means connected to said actuating member to shift actuating member along said control rod into alignment with a predetermined one of said follower fingers, said selector mechanism including a rotary control arm having a spiral groove defined therealong, a member having a portion in said groove and shiftable along said arm upon rotation of said control arm, said member being engageable with said actuating member to shift said actuating member into alignment with a predetermined follower finger, said selector means including means displaceable upon rotation of said control shaft to rock said rocker arm member and lift said actuating member off said follower fingers.

5. A control mechanism for a sewing machine having a frame, a needle bar mounted on said frame for swinging movement, and a swing member connected to said needle bar for effecting such swinging movement, comprising a rotatable cam shaft, a plurality of cam discs having a predetermined contour corresponding to an associated stitch pattern mounted on said cam shaft for rotation therewith, a follower shaft adjacent said cam discs, a plurality of follower fingers corresponding in number to said cams pivotally mounted on said follower shaft, a double arm rocking frame pivotally mounted adjacent said follower fingers having one arm connected to said swing member to control the movement thereof and another control arm extending alongside said cam discs, a cam actuating member shiftable along said control arm into alignment with a predetermined one of said follower fingers, means to bias said rocking lever to urge said cam actuating member into engagement with the cam with which it is in alignment, said follower fingers being oscillated by rotation of said cam discs to correspondingly oscillate said actuating member, said control arm, said rocking frame and said swing member to control the swinging movement of said needle, and selector means connected to said actuating member to shift said actuating member along said control rod into alignment with predetermined one of said follower fingers, said selector mechanism including a rotary arm having a spiral groove defined therealong, a member having ay portion in said groove and shiftable along said arm upon rotation thereof, said member being engageable with said actuating member to shift said actuating memberv into alignment with a predetermined follower finger, means holding a plurality of separate pictorial representations of stitch patterns, and pointer means connected to said actuating member and movable over said stitch patterns upon movement of said actuating member to indicate the stitch pat tern to be produced by the selected cam.

6. A control mechanism for a sewing machine having a frame, a needle bar mounted on said frame for swinging movement, and a swing member connected to said needle bar for effecting such swinging movement, comprising a rotatable cam shaft, a plurality of cam discs having a predetermined contour corresponding to an associated stitch pattern mounted on said cam shaft for rotation therewith, a follower shaft adjacent said cam discs, a plurality of follower fingers corresponding in number to said cam pivotally mounted on said follower shaft, a double arm rocking frame pivotally mounted adjacent said follower ngers having one arm connected to said swing member to control the movement thereof and another control arm extending alongside said cam, a cam actuating member shiftable along said control arm into alignment with a predetermined one of said follower lingers, means to bias said rocking lever to urge said cam actuating member into engagement with the cam with which it is in alignment, said follower lingers being oscillated by rotation of said cam to correspondingly oscillate said actuating member, said control arm, said rocking frame and said swing member to control the swinging movement of said needle, and selector means connected to said actuating member to shift said actuating member along said control rod into alignment with predetermined one of said follower lingers, said cam shaft being removably mounted in said frame, said cam discs being removable from said cam shaft.

7. A control device for controlling the movement of means for swinging a needle arm in a zig-zag sewing machine comprising a frame, a removable cam shaft rotatably positioned in said frame, a plurality of individual cams positioned on said cam shaft for rotation therewith, a plurality of follower fingers pivotally mounted intermediate their lengths adjacent said cams, a rocker frame pivotally mounted adjacent said follower lingers, said rocker frame having one arm connected to means for actuating said needle swinging mechanism and having another arm carrying a rod extending along the length of said follower lingers, an actuating member shiftable along said rod into alignment with a predetermined one of said lingers, means biasing said rocker frame to urge said actuating member into Contact with the linger with which it is in alignment, said linger being urged by said actuating member into engagement with one of said cams, and selector means including means to shift said actuating member along said rod for selecting a predetermined follower linger and associated cam.

8. A control mechanism according to claim 7, wherein said selector mechanism includes means to indicate a plurality of individual stitch patterns, and a pointer shiftable by operation of said selector means to indicate a stitch pattern in accordance with the follower fingers and cam selector.

9. A control mechanism according to claim 7, wherein said selector mechanism includes means to displace said rocker arm to shift said control member out of contact with said finger prior to its being moved out of alignment therewith.

10. A control mechanism according to claim 7, wherein said selector mechanism includes a positioning member disposed alongside said actuating member and engageable therewith, said positioning member being shiftable laterally along the full length of said row of said control follower lingers, and means to shift said positioning member.

References Cited in the file of this patent UNITED STATES' PATENTS 1,769,439 Lee July 1, 1930 2,172,623 Pitney Sept. l2, 1939 2,743,622 Haupt May l, 1956 2,832,302 Gegauf Apr. 29, 1958 2,862,468 Johnson Dec. 2, 1958 FOREIGN PATENTS 1,139,759 France Feb. 18, 1957 1,153,315 France Sept. 30, 1957 

